1. Technical Field
Example embodiments relate to a method for reducing power consumption and, more particularly, to a power-down method for a system having volatile memory devices.
2. Description of Related Art
Rapid development in digital apparatuses has led to a sharp increase in the amount of data to be processed by various systems using digital information. Also, to facilitate the processing of increased data, the various systems may include volatile memory devices with larger capacities or a larger number of volatile memory devices. In spite of an increase in the memory capacity of a system, the sharp increase in the amount of data may greatly affect the operation speed of the system especially when the system performs an initialization operation (e.g., booting operation) to process a large amount of data. For example, it may take about seven seconds or more for the system (e.g., a recently developed digital TV) to perform an initialization operation. Since an increase in an initialization time of a system weakens competitiveness, a method for shortening the initialization time of the system may be required.
Thus, to reduce an initialization time of a system, a method of operating volatile memory devices included in the system in a self-refresh mode to retain data when the system enters a power-down mode has been proposed. Recently developed systems may provide various power-down modes, such as a deep power-down mode, so that the systems can be booted using a remote controller even in the power-down mode, and a standby power may be supplied to the systems in the deep power-down mode. Thus, even in the power-down mode, the systems may set the volatile memory devices included therein to a self-refresh mode using a standby power to retain data, and be rebooted using the retained data so that a data loading speed can be reduced to increase an initialization speed.
However, as environmental problems are at issue, regulation of standby-power consumption has been strengthened. When the system is in the power-down mode, power consumed by a volatile memory device to perform a refresh operation in the power-down mode may take up a large part of the entire standby power.